This invention in general concerns improved performance for a vacuum cleaner when used in an auxiliary cleaning mode, and in particular concerns the provision of increased suction force in an auxiliary cleaning hose attached to an upright vacuum cleaner main cleaning head by partially relieving a common suction motor of such vacuum cleaner from relatively non-productive loads during such auxiliary cleaning.
Vacuum cleaners of different kinds have heretofore been provided with a variety of suction systems, including some of the type having twin suction air channels with suction force therein provided by a common suction motor. Furthermore, when such a twin air channel system is employed in a vacuum cleaner having a main cleaning head defining a principal suction area, it has also been known to in general provide for attachment of an auxiliary hose to such cleaning head for auxiliary cleaning at an alternate suction area with attachments such as crevice tools, dusting brushes, specialized upholstery nozzles, and the like. In particular, the auxiliary hose may be attached to the cleaning head in such manner as to divert suction air flow within one of its two air channels from the principal suction area to the auxiliary hose. However, "non-productive" suction air flow typically continues unimpeded in the other air channel in systems which have only a single common suction motor means for providing suction force in both of the air channels.
The present invention recognizes and brings to light certain improvements in such prior general twin suction air channel systems which particularly result in improved performance during auxiliary cleaning. In particular, the present invention recognizes that interruption of air flow in the suction air channel not associated with an auxiliary cleaning hose will result in a partial unloading or relieving of load from the above-mentioned common suction motor. This occurs, in general, because the commonly-driven fan assembly for such air channel essentially is free to turn without having to do the former work of perpetuating suction air flow (which is selectively interrupted). The present invention also recognizes that interruption of suction air flow in such suction air channel in no way detrimentally impacts vacuum cleaner performance relative the above-described auxiliary cleaning since such suction air flow produces no suction force in the auxiliary cleaning hose.
Moreover, not only does a reduction in the common suction motor load (without any loss of or detriment to auxiliary cleaning power) tend to improve suction motor life and reduce maintenance costs thereof, but it also advantageously permits an increase in the operational speed of such suction motor without requiring any electronic motor control or regulation. Since the rotational speed of the suction motor is directly proportional to the strength of the suction air flow ultimately established in the auxiliary hose, an increase in such rotational speed actually provides correspondingly increased suction air flow (i.e. cleaning power or performance) with the auxiliary hose. Accordingly, it is one general object of the present invention to provide improved auxiliary cleaning performance for a vacuum cleaner of the type having a commonly-powered twin suction air channel system.
It is yet a more particular object of the present invention, especially when adapted for use with an upright vacuum cleaner (i.e. having an extended control handle pivotably mounted on a main cleaning head) having two or more suction air channels, to provide means for simply and efficiently interrupting the suction air flow in the appropriate air channel (or channels) for achieving the more general objects of the invention, as mentioned above. In such upright vacuum cleaner embodiments, it is yet another more particular object of the present invention to achieve selected interruption of the appropriate air channel(s) by selective manipulation of the extended handle of such upright vacuum cleaner.
While different presently disclosed features and their equivalents may be collected to variously form given constructions of an embodiment in accordance with the present invention, and while those of ordinary skill in the art will recognize that various features disclosed herein may be practiced with a variety of types of vacuum cleaners so as to achieve the stated advantages of this invention, several exemplary embodiments in accordance with the present invention are particularly disclosed herewith. For example, one particular construction in accordance with this invention is directed to a vacuum cleaner adapted for use with auxiliary cleaning attachments, such vacuum cleaner comprising: a chassis having a main suction intake port area; suction motor means, supported on such chassis; first and second fan means, commonly driven by suction motor means, for establishing respective suction air flows within the chassis; first and second suction channel means, defined within the chassis, for respectively guiding the suction air flows between the respective fan means and the main suction intake port area so that dust and dirt adjacent the main suction intake port area may be suctioned into the chassis directed towards the fan means along the respective suction channel means; and auxiliary cleaning means for selectively alternatively directing suction air flow within the first suction channel means to a desired alternate suction area outside the chassis for suctioning dust and dirt from adjacent such alternate suction area instead of from adjacent the main suction intake port area, while also temporarily causing interruption of suction air flow within the second suction channel means so as to remove from the second fan means the work load of moving air flow within the second suction channel means, which thereby relieves part of the commonly-driven load of the suction motor means resulting in relatively increased operational speed for the first fan means and correspondingly increased suction air flow in the first suction channel means and at the alternate suction area.
In such an exemplary embodiment, the auxiliary cleaning means may for example particularly include an attachment port with an openable accessory door, adapted to facilitate operative association of an auxiliary cleaning hose with the first suction channel means, and may further include a pair of exhaust ports for exhausting discharge from the fan means, the exhaust ports being structurally distinguished to facilitate differential engagement thereof so that the appropriate (i.e. "non-productive") suction air flow may be interrupted. As further example of such embodiment, the structural distinctions may include one of the exhaust ports extending relatively further rearwardly than the other so as to engage and be sealed by part of a dust bag of an upright vacuum cleaner whenever the handle of same is pivoted generally to an upright position.
Yet another exemplary embodiment incorporating features of the present invention concerns an upright vacuum cleaner with improved auxiliary attachment cleaning, such vacuum cleaner comprising: a mobile chassis comprising a main cleaning head having a main dirt intake opening; a suction motor, carried on the chassis, and having a common output shaft means; a pair of fan elements, one each respectively attached to said common output shaft means, for being rotatably driven by the motor as a common load thereon; fan cover means respectively surrounding each of the pair of fan elements, and providing a suction intake port and a compression output port for each one of the pair; a pair of air channels defined by and within the chassis, one each respectively interconnecting each suction intake port with the chassis main dirt intake opening so as to form an air passage therebetween for suction force established by rotation of the fan elements, so that dirt situated exterior to the chassis and adjacent the main dirt intake opening thereof may be suctioned into the air channels by the suction force established therein with the fan elements; a pair of exhaust ports carried on the chassis and associated with the respective fan cover means output ports so as to conduct discharge therefrom to the exterior of the chassis; handle means, pivotably attached to the chassis, for guiding same; and bag means, supported on the handle means for movement therewith and interconnected with the chassis so as to receive discharge from the two exhaust ports; wherein one of the exhaust ports extends from the chassis an amount adequate so as to be sealed by contact with the bag means whenever same is pivoted with the handle means to a generally upright position, which sealing has the effect of precluding suction air flow in the corresponding fan cover means and air channel so as to in turn reduce the common load on the motor, whereby the rotational speed of the suction motor output shaft means is relatively increased, resulting in corresponding relatively increased suction force in the other air channel, the other air channel being adapted for selected alternative operative association with auxiliary attachment tools.
Still another exemplary embodiment of this invention is represented by an upright vacuum cleaner adapted for principal cleaning with a mobile cleaning head and alternative cleaning with auxiliary attachment tools removably associated with such cleaning head, such vacuum cleaner comprising: a wheel-supported mobile cleaning head having a main chassis, such chassis having a forwardly-located principal suction intake area, and a pair of suction air channels formed rearwardly from such intake area, situated along generally opposite sides of the chassis, and terminating adjacent the rear of the chassis on such respective opposite sides thereof; a suction motor situated adjacent the chassis rear and located generally between the air channel terminations, such motor having a central drive shaft axially aligned between such air channel terminations and extending outward from opposing axial sides of the motor; a pair of fan blade assemblies, one each ofwhich is mounted on the motor drive shaft on a given axial side of the motor, for being rotated by the motor as a common load thereof in a plane generally perpendicular to the axis between the air channel terminations; a pair of covers, one each extending circumferentially about each fan blade assembly, and each having an exhaust opening situated on the rearward side of the chassis; a pair of generally cone-shaped members, one each interconnecting an axially outward side of each cover with a respective one of the air channel terminations, each such coneshaped member defining a central opening therein for the passage of suction air flow through its respective air channel induced by the rotation of its respective fan blade assembly; a pair of exhaust ports supported on the rear of such chassis and interconnecting respectively with the exhaust openings of each fan blade assembly cover, one of the exhaust ports having a free end extending relatively further rearwardly from such chassis than the other, the extended exhaust port corresponding with a predetermined one of such air channels; a pivoting control handle attached adjacent the rear of the mobile cleaning head for guiding same; a dust bag supported generally along the length of the control handle for pivoting movement therewith relative the chassis, and having a lower end opening thereof which surrounds the pair of exhaust ports; a relatively rigid dirt tube supported internally within such dust bag and operatively interconnected with the exhaust ports so that same at least partially extend into a lower end opening of the dirt tube, such dirt tube having an upper end opening to permit dirt and air forced into the lower end thereof from the exhaust ports to be guided upwardly through and enclosed within the dirt tube so as to be deposited into the top of the dust bag; and an attachment port, associated with the air channel other than the predetermined one thereof, and adapted for selectively permitting attachment of an auxiliary hose to the cleaning head with a flange of such hose introduced into the other air channel for diverting suction air flow within the other air channel into such hose instead of from the principal suction intake area, such hose being adapted for use with auxiliary cleaning implements manipulated independently of the mobile cleaning head; wherein, during auxiliary cleaning with an auxiliary hose attached to the cleaning head, the control handle may be pivoted upward an amount adequate such that the relatively extended exhaust port free end is closed against an internal rear wall of the rigid dirt tube so that suction air flow within the corresponding predetermined one air channel is prevented which in turn removes air flow load from the corresponding fan blade assembly, whereby the common load on the suction motor is relatively reduced so that the rotational speed of the drive shaft thereof is relatively increased for corresponding increased suction air flow in the other air channel for improved auxiliary cleaning.
Those of ordinary skill in the art will recognize numerous modifications and variations which may be made to the above exemplary embodiments of this invention, and particularly will recognize equivalent substitutions, reversal of parts, and the like which may be practiced when applying features of the present invention to different given constructions or types of particular vacuum cleaners, all of which variations are intended to fall within the spirit and scope of the present invention by virtue of present reference thereto.